Now I wake up every morning and see a gray area outside. The aerosol system composed of dust, sulfuric acid, nitric acid and so on in the air causes visual obstacle, which is called haze. Many people wonder whether to wear masks in winter? Let's first understand the consequences of not wearing a mask.
In 2012, China issued a new ambient air quality standard, which is characterized by the concentration of six air pollutants. This is AQI - air quality index. The meteorological agency will monitor the concentration of sulfur dioxide, nitrogen dioxide, PM 10, PM 2.5, ozone and carbon monoxide in the air, calculate the air quality sub index of each pollutant, select the maximum value as the current air quality index, and update it every hour.
Among the six testing items, the most worrying is the inhalable particles and fine particles, namely PM 10 and PM 2.5. The diameter of these solid pollutants is less than 10 microns or 2.5 microns, which is invisible to the naked eye, but it is very harmful to health.
PM 10 and PM 2.5
A 20-year study showed that when the concentration of PM 2.5 in the air was higher than 10 μ g / m3 for a long time, the risk of death increased. For every 10 μ g / m3 increase in concentration, the total risk of death will increase by 4%, the risk of death from cardiopulmonary disease will increase by 6%, and the risk of death from lung cancer will increase by 8%.
People are spending more and more time on the road. Shanghai is the city with the longest average commuting time in China. People spend an average of 52 minutes a day commuting between home and office.
We can roughly estimate: suppose the average concentration of PM2.5 is 100 μ g / m3, it takes an hour to commute every day, works for 35 years, works for 300 days every day, breathes 10 times per minute, inhales 2000 ml of air each time & hellip & hellip; In your career, you will inhale 1.26g PM2.5 (PM2.5 concentration unit is microgram / m3, which is 1260000 microgram & hellip;). Given the respiratory output, the amount of inhalation seems to be small, but they can bring a lot of inflammation, lung cancer, and even cardiovascular health risks - just during commuting time.
So in haze weather, we must wear masks!